On 4/24/20 10:01 PM, Mathieu Poirier wrote: > This patch prevents the firmware image from being displayed or changed > when the remoteproc core is synchronising with a remote processor. This > is needed since there is no guarantee about the nature of the firmware > image that is loaded by the external entity. > > Signed-off-by: Mathieu Poirier <[email protected]> > --- > drivers/remoteproc/remoteproc_sysfs.c | 24 +++++++++++++++++++++++- > 1 file changed, 23 insertions(+), 1 deletion(-) > > diff --git a/drivers/remoteproc/remoteproc_sysfs.c > b/drivers/remoteproc/remoteproc_sysfs.c > index 7f8536b73295..cdd322a6ecfa 100644 > --- a/drivers/remoteproc/remoteproc_sysfs.c > +++ b/drivers/remoteproc/remoteproc_sysfs.c > @@ -13,9 +13,20 @@ > static ssize_t firmware_show(struct device *dev, struct device_attribute > *attr, > char *buf) > { > + ssize_t ret; > struct rproc *rproc = to_rproc(dev); > > - return sprintf(buf, "%s\n", rproc->firmware); > + /* > + * In most instances there is no guarantee about the firmware > + * that was loaded by the external entity. As such simply don't > + * print anything. > + */ > + if (rproc_needs_syncing(rproc)) > + ret = sprintf(buf, "\n"); A default name is provided in sysfs if no firmware is started/synchronised on boot. IMO providing an empty name here could be confusing. Perhaps a refactoring of this sysfs entry would be nice: - Normal boot (no firmware loaded) : empty name instead of a default name - auto_boot: name provided by the platform driver or default name ( current implementation) - synchronization: a predefined name such as Default, unknown, External, None,... > + else > + ret = sprintf(buf, "%s\n", rproc->firmware); > + > + return ret; > } > > /* Change firmware name via sysfs */ > @@ -39,6 +50,17 @@ static ssize_t firmware_store(struct device *dev, > goto out; > } > > + /* > + * There is no point in trying to change the firmware if loading the > + * image of the remote processor is done by another entity. > + */ > + if (rproc_needs_syncing(rproc)) { > + dev_err(dev, > + "can't change firmware while synchronising with MCU\n"); I don't know if you decide to keep "MCU" or not. If not the case you have also some other instances in your patch 9/14. Regards Arnaud > + err = -EBUSY; > + goto out; > + } > + > len = strcspn(buf, "\n"); > if (!len) { > dev_err(dev, "can't provide a NULL firmware\n"); >
